Study On The Key Technology Of Node Localization In Wireless Sensor Networks

In recent years, due to the rapid development of micro electronic technique, sensor technology, computer technology, wireless communication technology and network technique, Wireless Sensor Networks is also rapidly developed. WSN is on the basis of the computer Internet, using wireless data communications,RFID, etc. tecology,collecting environment variables in the network by each sensor node; each senor can exchange information and the monitoring efficiency is high,so WSN is the rapid development of the new achievements of human science and technology.As the key technology of Wireless Sensor Networks (WSNs), Self-localization Technology plays an important role on the practical applicability, veracity and effectiveness for Wireless Sensor Networks. How to accuratly, rapidly, steady, convenient feasibly, low power consumption locate each unknown node in WSN has become a crucical research topics.This paper firstly analyzes the Wireless Sensor Networks location technology. Introducing various localization algorithm, analyzing and comparing the advantages and disadvantages of various positioning technology, some problems in the current research orientation were pointed out and the direction of the improved performance is clear.Secondly, aiming at the issues of low efficiency, large positioning error caused by distance-measuring error in the node positioning method of more anchor nodes,a node positioning method based on Single anchor node is proposed. Through the analysis of the effect on obstructions to signal reception, metal absorption separation screen radio waves is designed besides the anchor node, which is around the anchor node. It makes the previous signal intensity decay, causes the signal receiving region of anchor nodes change and the signal reception state of anchor nodes is constantly changing. Using the state of the whole system when the signal reception state changes to work out the position of the unknown nodes. The simulation results show that this method controls positioning error effectively, improves the utilization efficiency of anchor nodes and reduces the computational cost.It has a broad application prospects in short distance and node localization field of small area.The paper also uses the PC computer, EMIO-WGB-1kit,80C51microcontroller and its accessories to build a single anchor node localization system. It uses assembly language and NesC language to programme for microcontroller and sensor nodes respectively and combines TinyOS operating system to achieve the method of single anchor node positioning. The data information is outwardly transmitted through a radio signal transmission from the unknown nodes.Anchor node is located and operated by the change of signal reception state and localization information is transmitted through the serial port to PC computer. This positioning system is used to locate the unknown nodes and analyze its error.